What did Tek use for EDA on their early stuff? I've seen boards on some scopes that definitely look like they were made digitally, but of course there isn't much info on early EDA anywhere online sinc

Oh I already performed that test, Albert. 5 9 volt batteries plugged into each other in series with my meter, diode checked it. Sure enough, worked just fine. wrote:

Hmm. I thought maybe a higher anode voltage would cause more attraction, thus needing a lower grid voltage to compensate? Maybe it doesn't work that way. Hmf. Quite confusing, indeed. Maybe it isn't t

The rear panel is actually a breeze to remove, just 4 screws and it pops off, without removing anything. Theres a little white cap on the bottom of the CRT socket that comes off to expose the connecto

with an open HV box (anode disconnected), grid is about 130 volts south of the cathode, seemingly normal for this CRT. In fact I can actually see a trace on-screen with trace-finder on, without the 11

Hm, well I suppose nothing to worry about then. I'm honestly clueless at this point

Recovers for about 1-1.5 seconds then comes back. And its a drop down in brightness, back down to a normal level. I'm not sure whether or not its linear, I could try and do some tests, but feedback is

Damn, apparently groups io doesnt like images. Here's a host. Thats 20 microseconds/div by the way, frequency looks fine according to databook. https://ibb.co/f2hdnBz gmail.com@groups.io> wrote:

Admittedly, however, the more I look at this machine, the less sure I am that it must be the HV section. This trace shows the driving transistor Q1430's collector voltage, not only incredibly shaky, b

Yep, I cleaned my contact points to a shiny polish to make sure, they were pretty darn dirty. And yes, physically on top of each other, there's 3. And none of those caps are measuring infinite, 10M or

Also potentially interesting, C1449 measures about twice the DC impedance on my meter as the other two similar caps its stacked on... as well as giving very erratic capacitance measures. Possible bad

I did your test, just put the battery across the diode terminals in reverse, measured no voltage on those resistors at all. In fact, I also measured the current entering the circuit, completely nothin

Diode tests normal according to Albert's tests... maybe leaky cap is right? Damn this is getting irritating yahoo.com@groups.io> wrote:

Yeah I'm an idiot, the diode just has a big voltage drop/fwd voltage. Also as Roger mentioned, I measured R1404 to be about .85M, .15 away from its spec of 1M. gmail.com@groups.io> wrote:

Also HV diode D1440 measured 8M across with my meter and 10M in reverse. Is this just because of the low voltage in my meter, or is this a bad diode? gmail.com@groups.io> wrote:

Albert, the R1447 measures from 0 to 1.28M from wiper to the C1440 end, and 1.28M from end to end (Pot is supposed to be 2M according to schema). Since I already cracked open the HV, I decided to meas

Albert, I've read all of your messages, I've just been attempting to rule everything out before having to tear into the HV supply, though at this point I suppose its necessary. Wonderful.

I was going to inspect the resistor chain individually, but that would involve desoldering of the entire HV section. As much as I love the rest of this unit, hiding a bunch of stuff under a panel of s

Ok Roger, I've been meter checking around the transistors on the Z axis board, like you said may be bad, as well as checking points mentioned by Arden, and I've discovered something interesting. Z axi

I created a thread a few days ago about my 454, and believe I have isolated the issue, in its -1960v supply. The HV reg is totally off, which is causing my grid voltage to be far too high, and as an e